The physical basis of the reaction of humans to low blood glucose by demonstrations of anger is the high energy needs of the human brain. The brain uses about 20 percent of the energy that the average person takes in on a daily basis. Low energy to the brain was correlated with lower levels of self-control by this research.

A group of 107 couples checked their blood glucose levels before breakfast and before bedtime for 21 days in the experiment. The participants were requested to record their feelings about the general state of their relationship when they took their blood glucose readings. The couples also recorded how angry they were with their spouse when they took their blood glucose measurements.

As a check on the accuracy of self-reported levels of anger, the participants were asked to push pins into a voodoo doll representing their spouse. The number of pins and the placement of the pins indicated the level of anger the individual felt toward their spouse. A separate test allowed the individuals to blast their spouse with noise depending n how angry they were with their spouse. The spouse never actually heard the noise.

The lower the level of blood glucose a person had represented higher levels of anger in both parts of the experiment. The researchers presume that anger is self-controlled in the majority of normal people. The scientists suggest eating something sweet before having that “serious talk” with your spouse.

The research results can be extended to other relationships that are not marital or romantic. Drinking a glass of apple juice before dealing with a difficult teen may produce more positive results. If your boss is an ogre in the afternoon, then give him a sweet treat to improve his mood.